Guide alignment system and method

ABSTRACT

An orthopedic device includes a patient-specific acetabular guide that can be used for preparing an acetabulum of a patient to receive an acetabular implant and/or placement of an acetabular prosthesis. The acetabular guide has a body with an outer three-dimensional surface configured to match an acetabulum of a specific patient&#39;s hip joint designed from data of the patient&#39;s hip joint. The acetabular guide can further include a peripheral annular rim.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.61/789,255, filed Mar. 15, 2013. The entire disclosure of the aboveapplication is incorporated herein by reference.

FIELD

The present teachings relate to an acetabular guide and particularly toa patient-specific guide and various associated instruments.

INTRODUCTION

The present teachings provide a patient-specific acetabular guide andassociated instruments for implanting an acetabular implant into anacetabulum of a patient for hip joint arthroplasty.

SUMMARY

The present teachings provide various instruments and methods forgenerally preparing the acetabulum of a patient to receive an acetabularimplant, such as, for example, an acetabular cup along an alignmentaxis. The alignment axis and various patient-specific guides and otherassociated instruments can be designed during a pre-operative plan usinga three-dimensional reconstruction of the patient's relevant anatomy,such as the pelvis or portions thereof, including the acetabular andperiacetabular areas of the pelvis. The three-dimensional reconstructioncan be based on medical images, including MRI, CT, ultrasound, or X-rayscans and prepared using commercially available imaging software.

The present teachings provide, for example, a patient-specificacetabular guide that can be used for preparing an acetabulum of apatient to receive an acetabular implant, such as an acetabular cup. Theacetabular guide has a dome-shaped body with a peripheral annular rimand an outer three-dimensional surface configured to match an acetabulumof a specific patient's hip joint from three-dimensional medical imagesof the patient's hip joint during a preoperative plan for the patient. Apatient-specific registration guide can be permanently or removablyattached to the peripheral rim. The patient-specific registration guidehas a longitudinal bore defining a patient-specific alignment axis withan alignment orientation configured for guiding an acetabular implantfor the patient during the preoperative plan of the patient. Theregistration guide has a patient-specific undersurface configured tomate with a corresponding portion of a periacetabular surface and/oracetabular rim surface of the acetabulum of the patient.

In some embodiments, the acetabular guide can include a plurality ofspaced-apart registration hooks. Each registration hook can extend fromand be attached to the peripheral rim of the acetabular guide. Eachregistration hook has a patient-specific undersurface configured to matewith a corresponding surface of the acetabular rim of the patient'sacetabulum.

The present teachings also provide a method for hip joint arthroplasty.The method includes inserting a patient-specific acetabular guide intoan acetabulum of a patient. A patient specific undersurface of adome-shaped body of the acetabular guide mates substantially as negativeof a corresponding surface of the acetabulum. At least onepatient-specific registration hook extends from a peripheral rim of theacetabular guide over a portion of an acetabular rim of the acetabulum.The method includes inserting an alignment pin into the patient's bonethrough a bore of a patient-specific registration guide. Thepatient-specific registration guide is removably attached to theperipheral rim of the acetabular guide. The patient-specificregistration guide is preoperatively configured to define apatient-specific alignment orientation for inserting an acetabularimplant. The method includes removing the acetabular guide withoutremoving the alignment pin and inserting an acetabular implant along anorientation parallel to the alignment pin.

In some embodiments, the acetabular guide can be inserted into theacetabulum using an inserter with a removable adapter element. A distalbore of the adapter element can be coupled to a first post of theacetabular guide. A second post of the acetabular guide can held betweenfirst and second flanges extending from the adapter element.

Further areas of applicability of the present teachings will becomeapparent from the description provided hereinafter. It should beunderstood that the description and specific examples are intended forpurposes of illustration only and are not intended to limit the scope ofthe present teachings.

BRIEF DESCRIPTION OF THE DRAWINGS

The present teachings will become more fully understood from thedetailed description and the accompanying drawings, wherein:

FIG. 1A is a front isometric view of a patient-specific acetabular guideaccording to the present teachings;

FIG. 1B is side isometric view patient-specific acetabular guide of FIG.1A;

FIG. 2A is top isometric view of the patient-specific acetabular guidewith an insertion handle, according to the present teachings;

FIG. 2B is side plan view of the patient-specific acetabular guide withan insertion handle, according to the present teachings;

FIG. 3A is an isometric environmental view of the patient-specificacetabular guide of FIG. 1;

FIG. 3B is an isometric environmental view of the patient-specificacetabular guide of FIG. 1 with an inserter attached;

FIG. 4 is another isometric environmental view of the patient-specificacetabular guide of FIG. 1 and an alignment pin; and

FIG. 5 is an isometric environmental view of an acetabular implant.

Corresponding reference numerals indicate corresponding parts throughoutthe several views of the drawings.

DETAILED DESCRIPTION

The following description is merely exemplary in nature and is in no wayintended to limit the present teachings, applications, or uses.

The present teachings generally provide patient-specific acetabularalignment guides, inserters and/or other associated instruments for usein orthopedic surgery, such as, for example, in joint replacement orrevision surgery for the hip. The patient-specific alignment guides andassociated instruments can be used either with conventional or withpatient-specific implant components prepared with computer-assistedimaging methods based on medical scan of the specific patient.

As described in U.S. Pat. No. 8,092,465, issued Jan. 1, 2012, and U.S.Patent Application Publication No. 2012/0226283, filed Feb. 21, 2012,both of which are incorporated by reference herein, during apreoperative planning stage, imaging data of the relevant anatomy of apatient may be obtained at a facility, including a doctor's office. Theimaging data may include, for example, a detailed scan of a pelvis, hip,knee, ankle or other joint or relevant portion of the patient's anatomy.The imaging data may be obtained using an MRI, CT, and X-Ray, ultrasoundor any other imaging systems. The imaging data obtained may be used toconstruct a three-dimensional computer image of the joint or otherportion of the anatomy of the patient and prepare an initialpreoperative plan that may include bone or joint preparation, such asplanning for resections, milling, reaming, broaching, as well as implantselection and fitting, design of patient-specific guides, templates,tools and alignment protocols for the surgical procedure. Additionally,physical modes of the patient's joint and associated bones may beprepared for visualization and trialing of the guides and implants priorto the surgical procedure.

Computer modeling for obtaining three-dimensional computer images of therelevant patient's anatomy may be provided by various computer aideddrafting (CAD) programs, applications and/or software commerciallyavailable from various vendors or developers, such as, for example, fromby Object Research Systems or ORS, Montreal, Canada. The computermodeling program or other application may be configured and used to plana preoperative surgical plan, including planning various bonepreparation procedures, to select or design/modify implants and designpatient-specific guides and tools. The patient-specific guides and toolsmay include patient-specific prosthesis components, and patient-specifictools, including reaming, broaching, milling, drilling or cutting tools,alignment guides, templates and other patient-specific instruments.

The preoperative plan may be stored in any computer storage medium, in acomputer file form or any other computer or digital representation,including three-dimensional graphical files or digital data sets. Thepreoperative plan, in a digital form associated with interactivesoftware or other application, may be made available via a hard medium,a web-based or mobile or cloud service, or a portable device that mayhave access to a cellular network. The plan may be provided via thevarious systems or media to the surgeon or other medical practitioner,for review. Using the interactive software or application, the surgeonmay review the plan, and manipulate the position of images of variousimplant components relative to an image of the anatomy. The surgeon maymodify the plan and send it to the manufacturer with recommendations orchanges. The interactive review process may be repeated until a final,approved plan, is sent to a manufacturing facility for preparing actualphysical components. In various embodiments, physical and digitalpatient-specific bone models, guides, and instruments may be providedpreoperatively to the surgeon for trialing and marking.

After the surgical plan is approved by the surgeon, patient-specificimplants and associated tools, including, for example, alignment guides,cutting/milling/reaming/broaching or other tools for the surgicalpreparation of the joint or other anatomy portion of the specificpatient may be designed using a CAD program or other three-dimensionalmodeling software, such as the software provided by Object ResearchSystems or ORS, Montreal, Canada, for example, according to thepreoperative surgical plan. Patient-specific guides and otherinstruments may be manufactured by various stereolithography methods,selective laser sintering, fused deposition modeling, or other rapidprototyping methods, and/or computer controlled machining. In someembodiments, computer instructions of tool paths for machining thepatient-specific guides and/or implants may be generated and stored in atool path data file. The tool path data may be provided as input to aCNC mill or other automated machining system, and the tools and implantsmay be machined from polymer, ceramic, metal or other suitable materialdepending on the use, and sterilized. The sterilized tools and implantsmay be shipped to the surgeon or medical facility for use during thesurgical procedure.

Patient-specific implants, guides, templates, tools or portions thereofare defined herein as those constructed by a preoperative plan for aspecific patient from three-dimensional images of the specific patient'sanatomy reconstructed from preoperative image scans of the patient. Thepatient-specific components are constructed to closely conform and mateor match substantially to a surface of the patient's anatomy. The matingor matching is generally as a negative mold, negative surface, orinverse or mirror surface of corresponding surface portions of thepatient's anatomy. The anatomical surfaces may include bone surfaceswith or without associated soft tissue, such as articular cartilage,depending on the particular procedure, implant and tool use. Minuteirregularities, such as those that would not affect placement of theguide, of the patient's joint surfaces need not be mirrored.

As discussed above, patient-specific alignment guides and implants aregenerally configured to match the anatomy of a specific patient andfit/register to the patient in only one position on a correspondingsurface of the specific patient because anatomic features that areunique to each patient may function as landmarks and may guide placementof the alignment guide or implant in only one position without the needof intraoperative image navigation, patient marking, or otherintraoperative guidance. The patient-specific alignment guides aregenerally configured and manufactured using computer modeling based onthe 3-D anatomic image of the patient and have an engagement surfacethat is made to conformingly contact and match, as discussed above, to acorresponding surface of a three-dimensional image/model of thepatient's bone surface (with or without cartilage or other soft tissue),by the computer methods discussed above.

Generally, the patient specific guide has an exterior surface thatdirectly contacts a selected portion of a selected region of a specificpatient's anatomy. For example, a patient specific guide can include anexterior surface (e.g. an external dome surface of an acetabular guide)that directly contacts about 80% of the patient's anatomy (e.g. aspecific patient's acetabulum) when properly positioned, including about90% contact, and about 98% contact. The exterior surface of the patientmatched guide may, therefore, substantially mate with the selectedportion of the anatomy. It is understood, however, that certain exteriorportions of a patient specific guide may not have substantial contactwith the patient, while other portions are designed to ensure contacteven when other portions are not contacting the patient. Thus, a patientmatched guide may have portions that are substantially patient matchedand have or may achieve the selected amount of contact with the patient.

The patient-specific alignment guides may include one or morecustom-made guiding formations, such as, for example, guiding bores orcannulated guiding posts or cannulated guiding extensions or receptaclesthat may be used for supporting or guiding other instruments, such asdrill guides, reamers, cutters, cutting guides and cutting blocks or forinserting pins or other fasteners according to a surgeon-approvedpre-operative plan. The patient-specific alignment guides may be used inminimally invasive surgery, and also in surgery with multipleminimally-invasive incisions. Various alignment guides and pre-operativeplanning procedures are disclosed in U.S. Pat. No. 8,092,465, issuedJan. 10, 2012; U.S. Pat. No. 8,070,752, issued Dec. 6, 2011; U.S. Pat.No. 8,133,234, issued Mar. 13, 2012; U.S. Publication No. 2009/0024131,published Jan. 22, 2009; U.S. Publication No. 2008/0114370 dated May 15,2008, now U.S. Pat. No. 8,298,237, issued Oct. 30, 2012; U.S.Publication No. 2011/0224674, published Nov. 15, 2011; U.S. PublicationNo. 2011/0184419, published Jul. 28, 2011; and U.S. Publication No.2012/0226283, published Sep. 6, 2012, all patents and applications areincorporated herein by reference.

Referring to FIGS. 1A-3B, the present teachings provide apatient-specific acetabular guide 100 and an acetabular guide inserter300. The acetabular guide 100 can be used in connection with variousother instruments to generally provide a patient-specific alignment axisA. The patient-specific alignment axis A is used to insert an alignmentpin 230 and generally to orient, insert, and implant an acetabularimplant or acetabular cup 250 in an acetabulum (or acetabulum cavity) 82of the patient, to facilitate guided reaming of the acetabulum 82, andgenerally guide any instruments and procedures relative to the alignmentaxis A or the alignment pin 230. The alignment axis A is determinedduring the preoperative plan from the three-dimensional image of the hipjoint of the patient as the axis along which the acetabular implant 250is to be centered and inserted. The alignment axis A is generallyperpendicular the acetabulum 82 and corresponding acetabular engagementsurface 252 of the acetabular implant 250. More specifically, withreference to FIG. 3B, the orientation (i.e., angles) of the alignmentaxis A can be selected and specified relative the axial plane (AP),sagittal plane (SP) and anterior pelvic plane (APP) of the pelvis 80.The coronal plane is a vertical plane that is orthogonal to the axialand sagittal planes (not shown). The anterior pelvic plane (APP) isdefined as a plane passing through the two anterior iliac spines and thepubic symphysis of the pelvis 80 of the patient. The APP may deviatefrom being parallel to the coronal plane when viewed in theweight-bearing profile of the patient (standing). Additionally, the APPplane may have a different orientation in the supine position. Thedeviation varies from patient to patient, such that the anterior pelvicplane cannot be relied on by the surgeon without additional informationto guide the acetabular implant and avoid impingement during motion. Theangle between the anterior pelvic plane and the coronal plane can bereferenced as a pelvic tilt and is zero when the anterior pelvic planeis parallel to the coronal plane. The present teachings determine apatient-specific axis for inserting an acetabular implant. Thepatient-specific alignment axis is physically and uniquely identified bythe orientation of an alignment pin 230 inserted into the bone using thepatient-specific acetabular guide and landmark registration incorporatedinto the acetabular guide during the preoperative plan. Specifically,the preoperative plan that is based on images of the hip joint of thepatient can accurately determine the orientation of the alignment axis Aand fix it intraoperatively via the patient-specific acetabular guide100 on the pelvis 80 of the patient to guide the surgeon during thesurgical procedure.

The patient-specific acetabular guide 100 can engage and register to theacetabulum 82 of the specific patient in a unique (only one) positionand can provide an accurate alignment axis A relative to the plannedorientation of an acetabular implant 250 (FIG. 4). The patient-specificacetabular guide 100 can also provide secure fitting and rotationalstability in a design that is lightweight and has compact size and smallbulk.

FIGS. 1A-3B illustrate a patient-specific acetabular guide 100 that hasa dome-shaped body 102 with a three dimensional patient-specificundersurface or outer surface 104 configured to contact and engage theacetabulum 82. The outer surface 104 is designed and/or formed to matchas a negative of a corresponding surface of the acetabulum 82 from thethree-dimensional image of the patient's hip joint. Thus, the outersurface 104 is formed to mate closely, such as to contact about 85% toabout 100% of the acetabulum 82 when positioned in the acetabulum 82.Thus, the outer surface 104 of the guide 100 includes a surface that maymirror or match the acetabulum 82.

The dome-shaped body 102 of the patient-specific acetabular guide 100can have one or more openings in the form of windows 106 that reduce theweight of the patient-specific acetabular guide 100 and provide improvedvisualization of the underlying anatomy. The dome-shaped body 102 canalso include additional holes or other apertures 109 for drilling holesin the acetabulum 82 and corresponding to holes 254 for fixation screwsof the acetabular implant 250. The dome-shaped body 102 of thepatient-specific acetabular guide 100 is bounded by a guide rim 108 inthe form of a closed-contour peripheral annular surface that may haveuneven, irregular, jagged or wavy shape that follows a correspondingshape of an acetabular rim 84 (and periacetabular surface) around theacetabulum 82 of the patient.

Additionally, the patient-specific acetabular guide 100 can include oneor more registration hook, which may also be referred to as extensionsor flanges, 110 that extend from the guide rim 108 along athree-dimensional curved surface around the acetabular rim 84 atdifferent and spaced-apart positions. The registration hooks 110 areconfigured to provide additional registration locations for thepatient-specific acetabular guide 100 by replicating correspondingunderlying surface portions or landmarks of the acetabular rim 84 in apatient-specific manner. Specifically, each registration hook 110 canhave a curved (three-dimensional) undersurface 112 that ispatient-specific and negative of the surface of the acetabular rim 84 atspecific locations selected as landmark locations during thepreoperative plan for the patient. Each registration hook 110 caninclude a hole 114 for receiving a fixation pin or other fixationelement (not shown) for attaching the patient-specific acetabular guide100 to the pelvis of the patient. In addition, the registration hooks110 may include a reinforcing ridge or rib. Selected reinforcing ribsinclude those illustrated and described in U.S. patent application Ser.No. 13/790,770, filed on Mar. 8, 2013, incorporated herein by reference.

The patient-specific acetabular guide 100 can include a removable ornon-removable registration and alignment guide 120 (referenced asregistration guide 120, for short) that has a longitudinal bore 124along the patient-specific alignment orientation A. A removable drillinsert 122 with a longitudinal bore 126 can be received concentricallyin the bore 124 of the registration guide 120. The wall of the bore 124of the registration guide 120 can define a taper that engages acomplementary taper 127 of an end of the removable drill insert 122. Thecomplementary tapers can ensure appropriate and selected alignment ofthe bore 124 and the insert bore 126. Thus, the bore 124 and the insertbore 126 can be concentric and coextensive.

The drill insert 122 can provide stability and wear resistance duringthe insertion of an alignment pin 230. The alignment pin 230 can beinserted along the alignment axis A and further have a longitudinal axisthat then extends along the alignment axis A. The alignment pin 230 caninclude a drill tip 231 that can drill into the bone of or near theacetabulum 82. The alignment pin 230 is received into the concentricbores 124, 126 of the registration guide 120 and the drill insert 122.Accordingly, the alignment pin 230 is oriented along the alignment axisA.

The drill insert 122 can be formed of a tough and/or strong material.For example, the drill insert 122 can be metallic and reusable, whilethe registration guide 120 and the acetabular guide 100 arepatient-specific and can be made of a softer material, such as a polymermaterial, and can be disposable. The tough material of the drill insert122 can engage the alignment pin 230 without deformation and/or wear toprotect the registration guide 120 from damage due to engaging thealignment pin 230. Further, during insertion of the pin 230 the drillinsert 122 generally is formed to not wear enough to allow movement ofthe pin 230 from the alignment axis A.

The registration guide 120 may have an undersurface portion that is apatient-specific undersurface 128 that can hook around or snap-on orotherwise engage and contact the guide rim 108 at a pre-defined markedlocation determined during the preoperative plan of the patient. Theregistration guide 120 that includes the patient-specific undersurface128 matches the surface of the acetabular rim 84 and/or periacetabulararea of the pelvis 80 of the patient at a corresponding location.

The bore 124 of the registration guide 120 and the bore 126 of the drillinsert 122 can have an open (i.e., non-continuous) periphery defining alongitudinal slit 133. The slit 133 may be configured to allow thepatient-specific acetabular guide 100 to be removed from the pelvis 80of the patient without removing the alignment pin 230 that is insertedinto the pelvis 80 and defines the alignment axis A. In other words, thepatient-specific acetabular guide 100 can be also removed by side orlateral motion relative to the slit 133 and the longitudinal axis A andnot necessarily by only motion along the alignment axis A or along thealignment pin 230.

The patient-specific acetabular guide 100 can include a first post 130and, optionally, a second post 132 (shown in phantom). Both of the posts130, 132 may extend from an interior surface 105 (opposite to outersurface 104) of the dome-shaped body 102 of the patient-specificacetabular guide 100. The post 130, as discussed herein, assists withplacement and alignment of the guide 100. Further, it is understood thatthe second post 132 is optional and need not be included with the guide100.

The first post 130 may, optionally, define a bore that passes throughthe dome-shaped body 102 of the acetabular guide for optional fixationto the acetabulum 82 using a pin or other fastener. The bore is notnecessary, however, and the post 130 can be a closed hollow post or asolid post. The first post 130 can be centrally located andperpendicular relative to a tangent to the dome-shaped body 102 of thepatient-specific acetabular guide 100 and the underlying surface of theacetabulum 82. The optional second post 132, if included, can be offsetrelative to the first post 130 in a radial direction relative to theperiphery of the guide rim 108. The second post 132 can be shorter inheight relative to the first post 130. The posts 130, 132 can be used toinsert the patient-specific acetabular guide 100 using an acetabularguide inserter, such as the acetabular guide inserter 300 shown in FIG.2-3B.

The post 130 can be an insertion and alignment post that extends fromand is formed with the guide 100. It is further understood, however,that the insertion post 130 can be interconnected with the guide 100 inany appropriate manner, such as with an adhesive or other fixationmechanism. Regardless, the post 130 may be formed to include anon-circular or non-cylindrical shape. For example, the post 130 caninclude a trapezoidal, oval, oblong or other selected shape. Thenon-circular shape can be viewed in cross-section of the post 130 and/oralong an axis extending along a height of the post 130.

The post 130 can include a post alignment axis 130 a that can have aspecific orientation relative to the guide 100, and particularly to thealignment axis A through the registration guide 120. The post alignmentaxis 130 a may be used to align the guide 100 relative to a selectedportion of the anatomy, including an anatomical landmark, as discussedfurther herein. The anatomical landmark can be predetermined in thepatient image, such as during planning the procedure. Accordingly, thepost 130, including a post alignment axis 130 a can assist inrotationally aligning the guide 100 relative to the acetabulum 82 in thepelvis 80. Moreover, the non-circular shape of the post 130 can assistin holding and engaging the guide 100 relative to a selected insertioninstrument 300 (FIGS. 2A and 2B), as discussed further herein. Moreover,the post 130 can include an external geometry that tapers towards a base131 of the post 130 near the internal surface 105 of the guide 100.Again, the taper of the post 130 can assist in engagement and fixationof the guide relative to the insertion instrument 300, as discussedfurther herein.

With particular reference to FIGS. 2A and 2B, the inserter 300 canengage the first post 130 near a first end 302 that defines an internalbore or capture area 304 that is complementarily shaped and/or mateswith an upper or top portion 133 of the post 130. As discussed above,the shape of the central post 130 can define the post alignment axis 130a. The complimentary internal bore 304 of the inserter instrument 300can also define an inserter bore axis that mates or aligns with the postalignment axis 130 a once the inserter 300 engages the post 130.Accordingly, the instrument 300 engages and may couple to the post 130in a selected and keyed manner. In the keyed manner the inserter 300engages the post 130 in a selected single orientation and position,which also allows the inserter 300 to be positioned at a singleorientation and position relative to the guide 100. The inserter 300,therefore, can be interconnected with the guide 100 and a selectedsingle orientation and position to allow for manipulating the guiderelative to the pelvis 80.

The first end 302 of the shaft 306 can further include a taper thatengages the external taper of the post 130. A female taper of thereceiving bore 304 coupling with the external taper of the post 130 canassist in holding and fixing the post 130, and the guide 100, relativeto the inserter handle 300. It is understood, however, that additionalattachment mechanisms can also be provided such as an interference fit,a snap fit, a screw or bolt that engages the post 130 relative to thehandle 300, or other appropriate connection mechanisms.

Additionally, the inserter 300 can include a shaft 306 that extends to ahandle 308. The handle 308 can be grasped by a user to manipulate theinserter 300 relative to the guide 100 for engaging the post 130. Oncethe inserter 300 is coupled to the post 130 the inserter can thenfurther translate and rotate the guide 100 relative to the pelvis 80once the handle 300 is engaged on the post 130.

Additionally, the inserter 300 can include an alignment portion, such,as a jig or alignment rod 310, which may be coupled to and/or formedwith the shaft 306 at an engagement or coupling region 312. Thealignment portion can be viewed exterior to soft tissue of the patientby a user during insertion and positioning the guide 100 from. Thus, theuser can know an alignment of the guide 100 by viewing the alignmentportion as the inserter 300 engages the post 130 in a single locationand orientation.

The coupling region 312 can include an internal thread to engage anexternal thread of the alignment jig or rod 310. Additionally, however,further connection mechanisms can be provided such as a slotted aperturewhich allows the alignment jig or rod to directly contact a pre-definedportion of anatomy or soft tissue. Alternatively, the alignment portion,such as the alignment jig 310, may be permanently fixed or manufacturedwith the shaft 306 as a single piece. Nevertheless, the alignment jig310 can extend from the shaft 306 along an alignment portion or jig axis310 a. The alignment portion axis 310 a of the alignment jig 310 can beformed to align with the post alignment axis 130 a of the post 130.Because the post 130 engages the internal bore 304 in the shaft 306 in asingle selected and predetermined location and orientation, the shaft306 will engage and align with the post 130 in a substantially singleorientation and position. Thus, the alignment jig 310, which defines thealignment axis 310 a, is aligned with the axis 130 a of the post 130. Itis understood, however, that the alignment jig 310 is not required andthat the handle 300 engaging the post 130 can provide appropriatefixation and alignment for a user, for purposes as discussed furtherherein.

With reference to FIGS. 3A and 3B, the guide 100 can be positioned inthe acetabulum 82 of the pelvis 80 in a selected manner. As discussedabove, the central post 130 defines the post alignment axis 130 a. Asthe inserter 300 is aligned with the axis 130 a, due to the engagementof the bore 304 with the post 130, the handle 300 can be visually viewedfrom exterior to the patient. Additionally, the alignment jig 310 canalso be positioned on a portion of the shaft 306 such that it is alsoexterior to the patient when the guide 100 is positioned near or withinthe acetabulum 82. It is understood, that when viewed from an exteriorof the patient included is viewing a portion exterior to soft tissue ofthe patient or a distance away from the patient such that a user, suchas a surgeon, can have a clear view of the alignment jig 310 and/or aportion of the inserter 300 while positioning the guide 100 within theacetabulum 82.

The post alignment axis 130 a can be extended exterior to the guide 100to allow for alignment with a portion of the pelvis, such as ananatomical landmark 400, which can include the Anterior Superior IliacSpine (ASIS), due to positioning of the guide 100 within the acetabulum82. The anatomical landmark can be predetermined, such as duringplanning of the procedure. The alignment axis A through the registrationguide 120 can also be selected during a pre-planning process. The designof the guide 100 can then be based on the predetermined landmark and thepredetermined location of the alignment axis A. The guide 100 can thenbe manufactured to have the post 130 with the post alignment axis 130 aformed relative to the alignment axis A such that alignment of the postalignment axis 130 a with the predetermined landmark will place thealignment axis A at the predetermined location and orientation.

Accordingly, the position of axis A relative to the acetabulum 82 can bepre-determined and can be positioned relative to the pelvis 80 due toregistration of the guide 100 within the acetabulum 82. As discussedabove, the guide 100 registers within the acetabulum 82 (i.e., bysubstantial matching or contact of the exterior surface 104 of the guide100 with the acetabulum 82) in substantially only a single location andorientation. Accordingly, the handle 300 can be used to position androtate the guide 100 in the direction of Arrow 410. The inserter 300 canbe used to sweep an arc of a selected length in either or bothdirections of arrow 410. The alignment jig 310 that defines the jig axis310 a that is aligned with the post alignment axis 130 a can all bedesigned to ensure that registration of the guide 100 occurs when thealignment axis A is at the selected pre-planned position within thepatient. Accordingly, via moving the handle 300, illustrated in FIGS. 2Aand 2B, the surgeon can clearly view the alignment jig 310 relative tovarious landmarks of the patient, such as the ASIS 400, such as fromexterior to soft tissue of the patient.

Rotating the guide 100 can move the post alignment axis 130 a of thecentral post 130 relative to the pelvis 80. For example, as illustratedin FIG. 3B, the post alignment axis 130 a of the post 130 can bepositioned to point toward or be aligned with an iliac crest 420 of thepelvis 80. Positioning of the post alignment axis 130 a′ of the centralpost 130 aligns the jig axis 310A′ of the jig 320 with the iliac crest420 as well. During the procedure, the surgeon can view that thealignment jig 310 is oriented or aligned with the iliac crest 420 anddetermine that the guide 100 must be rotated anteriorly or towards apubis 430. The user can then rotate the inserter 300 and the guide 100as needed, and generally in the direction of one of the arrowheads 410.Thus, the user can determine an appropriate movement of the guide 100 toposition the guide 100 relative to a pre-selected landmark, such as theASIS 400. The alignment jig 310 can assist and/or ensure that the guide100 is positioned and registered to the acetabulum 82 by allowing theuser to view the jig 310, or selected portion of the inserter 300.Again, this assists in rotational alignment of the guide 100 at leastbecause the inserter 300 engages the post 130 in the keyed manner.Accordingly, while the acetabular guide 100 will register within theacetabulum 82 at a selected single location and orientation, thealignment jig 310, viewed by the user, can assist in ensuring that theguide 100 is at a pre-selected or pre-planned location and increase thespeed of aligning the guide 100 relative to the pre-planned and selectedorientation.

It is understood that the guide 100 can be oriented relative to anyselected anatomical landmark that can be viewed and/or palpated by auser during the procedure. For example, it is understood that thecentral post 130 can be designed and positioned within the guide 100such that the post alignment axis 130 a is aligned with the iliac crest420 when the guide 100 is properly registered within the acetabulum 82.Accordingly, aligning the post alignment axis 130 a with the ASIS 400 isnot required for ensuring that the guide 100 is properly registered withthe patient, if a pre-planned or pre-determined orientation of the guide100 is selected as such that the axis 130A is to be aligned with adifferent landmark.

Nevertheless, based upon the pre-planned or pre-determined alignmentwith the selected landmark, the inserter 300 can be used to rotate theguide 100 relative to the acetabulum 82 during insertion and placementof the guide 100 within the acetabulum 82. Once appropriatelyregistered, the inserter 300 can be removed from the central post 130and the alignment pin 230 can be passed through the drill insert 120that has been positioned within the registration guide 120, asillustrated in FIG. 4. The alignment pin 230, when inserted through thedrill insert 122 that is positioned within the registration guide 120generally extends along the alignment axis A that is pre-plannedrelative to the guide 100. Again, by positioning the guide 100registered within the acetabulum 82 the alignment axis A is at thepre-planned and selected position relative to the acetabulum 82.Positioning of the alignment pin 230 through the drill insert 122 thatis positioned within the registration guide 120 and drilling it into thepelvis 80 positions the alignment pin 230 along the axis A.

The positioning of the guide 100, as discussed above, is assisted bypositioning the inserter 300 relative to the central post 130 to alignthe alignment jig 310, or other selected portion of the handle 300,along post alignment axis 130 a of the central post 130. The guide 100,therefore, could be properly registered relative to the patient byaligning the alignment jig 300 relative to a selected anatomicallandmark, such as the ASIS 400, at least via rotation of the handle 300and the guide 100, due to coupling with the handle 300. In this way, theinserter 300 may be used to rotationally position the guide 100 forplacement of the alignment axis A at the predetermined location andorientation for placement of the pin 230.

Once the alignment pin 230 is positioned within the pelvis 80, the drillinsert 122 can be removed generally along the alignment pin 230 and theguide 100 can be removed longitudinally and/or laterally relative to thealignment pin 230. The alignment pin 230, either directly or indirectly,can then be used to guide various portions of a procedure, such asreaming of the acetabulum 82 and/or positioning the acetabular implant250, as illustrated in FIG. 5. The acetabular implant 250 can bepositioned in the acetabulum with reference to the alignment axis A byaligning the acetabular implant 250, having the central axis A′, withthe alignment pin 230. Accordingly, as illustrated in FIG. 5, theacetabular implant 250 can be positioned aligned with the alignment axisA that has been pre-planned and determined relative to the pelvis 80.

Accordingly, it is understood that the patient-specific guide 100 can bepositioned within the acetabulum 82 of the patient in a pre-planned andregistered position. The positioning of the patient-specific guide 100can require axial movement to and/or within the acetabulum 82 androtational positioning within the acetabulum 82. The inserter 300 may becoupled relative to the central post 130, which is fixed to theacetabular guide 100 at a pre-planned and selected position, such that apost alignment axis 130 a of the post 130 can be aligned with apre-determined landmark. The inserter 300, including the alignment jig310 or other appropriate alignment portion, can be aligned with a postalignment axis 130 a of the central post 130 for viewing by a user.Viewing the alignment axis and/or the alignment jig 310 by the userduring insertion of the guide 100 into the acetabulum 82 can allow theuser to ensure appropriate positioning of the guide 100 within theacetabulum 82 by aligning the alignment jig 310 with a pre-determinedlandmark, such as the ASIS 410. Thus, the inserter 300 coupled in akeyed manner at a pre-determined orientation relative to the guide 100can be used to assist in ensuring and placing the patient-specific guide100 within the acetabulum 82.

According to various embodiments, when the guide 100 is placed in theacetabulum 82 in the predetermined location and orientation the guide100 is registered to the acetabulum 82. Generally, the registrationoccurs and/or is achieved due to the contact of the outer surface 104with the acetabulum either alone or with the various surfaces of theregistration hooks 110 and/or the surface 128. Thus, the guide 100 canbe registered to the acetabulum 82 of a specific patient in a specificand predetermined location and orientation.

Various patient-specific guides, secondary guides, reamers, guidehandles, inserters, impactors, support devices, electronic positionersand other instruments can be used in various combinations and based onsurgeon preferences or patient and preoperative or intraoperativecircumstances for preparing an acetabulum and guiding and implanting anacetabular implant along a preoperatively determined alignmentorientation. In this respect, tools and instrumentation providingredundant functionality and of different embodiments may provide to thesurgeon in a kit or per surgeon's request.

For example, adaptors and other instruments described above can beprovided and used in various combinations within the scope of themethods described herein.

The foregoing discussion discloses and describes merely exemplaryarrangements of the present teachings. Furthermore, the mixing andmatching of features, elements and/or functions between variousembodiments is expressly contemplated herein, so that one of ordinaryskill in the art would appreciate from this disclosure that features,elements and/or functions of one embodiment may be incorporated intoanother embodiment as appropriate, unless described otherwise above.Moreover, many modifications may be made to adapt a particular situationor material to the present teachings without departing from theessential scope thereof. One skilled in the art will readily recognizefrom such discussion, and from the accompanying drawings and claims,that various changes, modifications and variations can be made thereinwithout departing from the spirit and scope of the present teachings asdefined in the following claims.

What is claimed is:
 1. A method of placing a guide pin near anacetabulum with an acetabular guide system, comprising: coupling aninserter to a patient specific acetabular guide via a keyed post,wherein the keyed post is fixed relative to the patient specificacetabular guide; moving the patient specific acetabular guide into theacetabulum; rotating the patient specific acetabular guide relative tothe acetabulum with the coupled inserter; and determining an alignmentof the coupled patient specific acetabular guide with the inserter,including viewing an alignment jig, wherein the alignment jig isassociated with the inserter and extends from a shaft of the inserter.2. The method of claim 1, wherein coupling the inserter to the patientspecific acetabular guide via the keyed post includes coupling theinserter in a single predetermined location and orientation relative tothe patient specific acetabular guide via the keyed post.
 3. The methodof claim 1, wherein the keyed post defines a post alignment axis alignedwith the patient specific acetabular guide in a single location andorientation.
 4. The method of claim 3, wherein rotating the patientspecific acetabular guide relative to the acetabulum with the coupledinserter includes rotating the post alignment axis relative to theacetabulum with the coupled inserter.
 5. The method of claim 1, whereindetermining the alignment of the coupled patient specific acetabularguide with the inserter includes aligning at least one of the alignmentjig or a jig alignment axis with a predetermined anatomical landmark. 6.The method of claim 5, further comprising: registering the patientspecific acetabular guide within the acetabulum when at least one of thealignment jig or the jig alignment axis is aligned with thepredetermined anatomical landmark.
 7. The method of claim 6, wherein thepredetermined anatomical landmark is the anterior superior iliac spine.8. The method of claim 1, wherein determining the alignment of thecoupled patient specific acetabular guide with the inserter includesviewing the jig exterior to a soft tissue of a patient.
 9. The method ofclaim 1, wherein determining the alignment of the coupled patientspecific acetabular guide with the inserter includes viewing analignment portion of the inserter.
 10. The method of claim 9, furthercomprising: registering the patient specific acetabular guide within theacetabulum when the alignment portion is aligned with the predeterminedanatomical landmark.
 11. The method of claim 10, wherein thepredetermined anatomical landmark is the anterior superior iliac spine.12. The method of claim 1, wherein rotating the patient specificacetabular guide relative to the acetabulum with the coupled inserterincludes rotating the patient specific acetabular guide such that thepost alignment axis sweeps an arc relative to a predetermined anatomicallandmark.
 13. The method of claim 1, wherein coupling the inserter tothe patient specific acetabular guide via the keyed post includesengaging a non-circular internal bore of the inserter with anon-circular exterior surface of the keyed post.
 14. The method of claim13, wherein the non-circular exterior surface of the keyed post istrapezoid in cross-section.
 15. An acetabular guide system for placing aguide pin near an acetabulum, comprising: a patient specific acetabularguide, including: an exterior surface of the patient specific acetabularguide configured to have a geometry to register within the acetabulum ofa specific patient, and a keyed central post extending from an interiorsurface of the patient specific acetabular guide, wherein the keyedcentral post includes an exterior surface that defines a post alignmentaxis relative to the patient specific acetabular guide; and aregistration guide defining a guide bore extending exterior to theinterior surface, wherein the keyed central post defines a trapezoid incross-section, wherein the post alignment axis is at a fixed locationand orientation relative to the registration guide.
 16. The acetabularguide system of claim 15, further comprising: a guide inserter having anelongated shaft defining an internal bore; wherein the internal bore ofthe elongated shaft engages the exterior surface of the keyed centralpost to move the acetabular guide into the acetabulum.
 17. Theacetabular guide system of claim 16, wherein the internal bore includeshas an internal surface that is keyed complementarily to the exteriorsurface of the keyed central post; wherein the internal surface that iskeyed complementarily to the exterior surface of the keyed central postis configured to allow coupling of the guide inserter to the keyedcentral post in only one location and orientation.
 18. The acetabularguide system of claim 17, wherein the guide inserter is configured tocouple to the keyed central post so that the guide inserter isconfigured to at least rotationally move the patient specific acetabularguide.
 19. The acetabular guide system of claim 18, further comprising:an alignment jig coupled to the elongated shaft of the guide inserter;wherein the alignment jig defines an alignment axis that is configuredto be aligned with the post alignment axis when the guide inserter iscoupled to the keyed central post.
 20. The acetabular guide system ofclaim 15, wherein the exterior surface of the keyed central post tapersfrom the interior surface of the patient specific acetabular guide to anend of the keyed central post.
 21. The acetabular guide system of claim20, wherein the internal bore includes has an internal surface that is afemale taper that is keyed complementarily to the tapered exteriorsurface of the keyed central post; wherein the internal surface that iskeyed complementarily to the exterior surface of the keyed central postis configured to allow coupling of the guide inserter to the keyedcentral post in only one location and orientation.
 22. The acetabularguide system of claim 21, wherein the guide inserter is configured tocouple to the keyed central post so that the guide inserter isconfigured to at least rotationally move the patient specific acetabularguide.
 23. The acetabular guide system of claim 21, wherein the femaletaper and the exterior taper form a taper lock.
 24. The acetabular guidesystem of claim 21, further comprising: an alignment jig coupled to theelongated shaft of the guide inserter; wherein the alignment jig definesa jig alignment axis that is configured to be aligned with the postalignment axis when the guide inserter is coupled to the keyed centralpost.
 25. The acetabular guide system of claim 15, further comprising: apin guide insert defining an insert bore, wherein pin guide insert isplaced in the guide bore to guide a guide pin.
 26. The acetabular guidesystem of claim 25, further comprising: the guide pin configured to bepassed through the insert bore to engage a region of a pelvis near theacetabulum.
 27. The acetabular guide system of claim 15, wherein thepost alignment axis of the keyed central post is configured to bealigned with a predetermined anatomical landmark to allow registrationof the patient specific acetabular guide with the acetabulum and achievea predetermined placement of the registration guide.
 28. A method ofplacing a guide pin near an acetabulum with an acetabular guide system,comprising: providing a patient specific acetabular guide comprising:forming an exterior surface of the patient specific acetabular guideconfigured to have a geometry to register within the acetabulum of aspecific patient; forming a keyed central post extending from aninterior surface of the patient specific acetabular guide, includingforming an exterior surface that defines a post alignment axis relativeto the patient specific acetabular guide; forming an internal bore of aguide inserter having an elongated shaft to engage the exterior surfaceof the keyed central post to move the acetabular guide into theacetabulum, an internal surface of the internal bore keyedcomplementarily to the exterior surface of the keyed central post sothat the internal bore is allowed to couple to the exterior surface ofthe keyed central post in only one location and orientation; forming analignment jig to align with the post alignment axis when the internalbore couples with the exterior surface of the keyed central post; andforming a registration guide defining a guide bore extending exterior tothe interior surface; wherein the post alignment axis is formed at afixed location and orientation relative to the registration guide. 29.The method of claim 28, wherein forming the exterior surface of thepatient specific acetabular guide configured to have a geometry toregister within the acetabulum of a specific patient includes acquiringimages of the specific patient and designing the exterior surface of thepatient specific acetabular guide to have a mating surface with theacetabulum of the specific patient.
 30. The method of claim 28, whereinforming the exterior surface of the patient specific acetabular guideconfigured to have a geometry to register within the acetabulum of aspecific patient includes acquiring images of the specific patient anddesigning the exterior surface of the patient specific acetabular guideto have a mirror surface of the acetabulum of the specific patient. 31.The method of claim 28, wherein forming the keyed central post includesforming the exterior surface of the keyed central post to taper from theinterior surface of the patient specific acetabular guide to an end ofthe keyed central post.
 32. The method of claim 31, wherein forming theinternal bore includes forming a female taper surface in the internalbore to be keyed complementarily to the tapered exterior surface of thekeyed central post so that the internal bore is allowed to couple to theexterior surface of the keyed central post in only one location andorientation.
 33. The method of claim 32, wherein the female taper andthe tapered exterior surface form a taper lock.
 34. The method of claim28, further comprising: forming a pin guide insert defining an insertbore, wherein the pin guide insert is placed in the guide bore to guidea guide pin.
 35. The method of claim 34, further comprising: providingthe guide pin to pass through the insert bore to engage a region of apelvis near the acetabulum.
 36. The method of claim 28, wherein formingthe keyed central post includes forming the exterior surface to definethe post alignment axis relative to the patient specific acetabularguide by defining the post alignment axis to be aligned with apredetermined anatomical landmark of the patient to allow registrationof the patient specific acetabular guide with the acetabulum andplacement of the guide bore at a predetermined position and orientationrelative to the acetabulum when the central post axis is aligned withthe predetermined anatomical landmark of the patient.
 37. A method ofplacing a guide pin near an acetabulum with an acetabular guide system,comprising: coupling an inserter to a patient specific acetabular guidevia a keyed post, wherein the keyed post is fixed relative to thepatient specific acetabular guide; moving the patient specificacetabular guide into the acetabulum; rotating the patient specificacetabular guide relative to the acetabulum with the coupled inserter;and determining an alignment of the coupled patient specific acetabularguide with the inserter, wherein coupling the inserter to the patientspecific acetabular guide via the keyed post includes engaging anon-circular internal bore of the inserter with a non-circular exteriorsurface of the keyed post.
 38. The method of claim 37, wherein thenon-circular exterior surface of the keyed post has a trapezoidcross-section.